With several days of extreme heat in the forecast, prolonged exposure could make matters worse according to Dr. Teresa Davis of Rush University Medical Center in Chicago.

"If there's multiple days in a row of your body being exposed to that type of heat it's harder for your body to recover especially the elderly," Davis said.

Forecaster Ben Deubelbeiss of The National Weather Service said things are expected to get even hotter next week in the Chicago area.

"Sunday we're expecting heat indexes right around a 100 degrees and probably a couple degrees warmer on Monday. A little bit of cool down on Tuesday as we get a weak cold front that pushes through the area but Wednesday and Thursday look to be the hottest days," Deubelbeiss said.